This transcript has been automatically generated and may not be 100% accurate.

... I ... here in the news as it searching for ... oil traders manipulate prices ... EU officials and they conducted unannounced inspections of oil giants BP Shell and Iowa ... investigators are looking into whether these companies in and reporting distorted prices to manipulate published oil prices ... the offices of heights any oil indexed publisher responsible for calculating dealing bank stocks ... were also inspected ... the companies in pots of their cooperating with the probe ... why isn't that a ... this is a two point five trillion dollar market and fees as part of the basis of commodity and derivatives deals around the globe ... the impact of the benchmark set by pots reverberate across hundreds and into index is worldwide ... oil benchmarks calculated ... throughout the day pot supporters gather information and deals with the offers that traders voluntary disclosures ... and then uses this information to formulate benchmark for various energy markets ... most of the trades happen in a thirty to forty five minute window at the end of each trading day ... after markets close afterburners published the benchmark prices that they say that's reflect the values of the energy markets ... how can oil prices the manipulated ... some traders say they made ... trades at pains to try to lower the price they paid for a while or raise the price to get for selling ... for example one trader told us he could sell some on Ottawa to try to drive down prices and ... and and south of the chip lead at the lower rate ... to do that in the days prior to the purchase he can offer to sell smaller quantities at a discount ... sometimes three to five dollars a metric ton below market rate ... in the end of the trading window you tripods to formulate their prices ... because that's the suspense part on information volunteered by chance rather than a comprehensive markets and a ... pack of well drive the price down ... and see trader money and a leader more substantial purchase what evidence is that of manipulation is taking place ... Cox says it's never seen evidence that traders have manipulated their benchmark prices and that its methodology is specifically designed to increase transparency in the market ... and safeguard against distortions ... Cox says the chain's its reporters to determine whether any trade seemed to see what the overall market ... but some traders told us that they often use these types of strategies in place thanks much ... they say such activity is legal because it doesn't involve colluding with competitors reporting think prices are other obviously forbidding the heated ... even so a nice that intention is to steal oil and stocks ... for the last return on tankers ...